This invention relates to the treatment of dental patients using a foam material. The treatment includes retraction of gingival margins, cushioning dental appliances, cleaning of tooth surfaces and the dressing of wounds in the mouth.
Although dentistry is a technically advanced art there remain areas in need of improvement and problems which require solutions.
One such area is the retraction of the gingival margin in preparation for subsequent subgingival curettage or for the taking of dental impressions. The management of the gingival tissue prior to the taking of a precise impression for prosthetic laboratory work has been among the most difficult procedures in dentistry. The tissue next to the working site must be pushed away from the prepared borders and, if possible, reduced in site.
Many different materials and methods have been used for this work including electrosurgical trophying, the pressing in of restriction rings, copper tubes, retraction sleeves, gingitage (trophying with rotary diamond points), vascularconstrictor-containing retraction cords, astringent substances contained in retraction cords, vascular-constrictor and/or astringent-containing gels and pellets, and the like.
These methods and materials of the prior art have been successful to varying degrees in accomplishing the preparation of gingival tissue for subsequent procedures. However, most of these materials have accompanying disadvantages. For example, the prior art methods and materials may result in sulcus borders which are not complete and not smooth. In other cases there is a substantial risk of postoperative tissue loss with aesthetically unsatisfying results. In some cases continual bleeding of the gums makes it difficult to take impressions. There are often manual difficulties for the dentist in using some of the prior art materials and procedures. Other of the prior art methods result in increased cardiovascular risk and sometimes in severe and lasting postoperative pain.
There are other needs in the field of dentistry which have not been adequately met in the past and which would benefit from new materials and methods. Although toothbrushing and the use of dental floss have long been accepted as means for cleaning teeth and stimulating gums, it would be an improvement to find a material or method which provided improved cleaning of tooth surfaces, especially at intricate shapes and in close passages between teeth and/or fixed prosthetic parts.
There has also been a long-felt need in the dental profession for a cushion material to fit between dental appliances and irritated gums. Such a material, which promotes heating and is readily applicable by the wearer of the appliance, would be especially useful.
There has also been a long-felt need in the dental profession for a more practical wound dressing which can be used in the mouth. Normal gauze and cloth bandages are not comfortably useful in a dental subject's mouth for long periods of time. Normal dental peridontal pressure packs become hard when wet so that they only protect the wound and do not apply a uniform pressure. Foam dressings, such as Dow Corning's SILASTIC.RTM. Foam Dressing, are known for use in open, granulating wounds. However, the system of components used to generate this foam dressing has a viscosity which, when first mixed, is not sufficiently high to be normally desirable in a respiratory pathway and the resulting foam composition is not sufficiently resistant to compression to meet the needs of dentistry described above. This prior art foam dressing also has the disadvantage of an unpleasant taste. Such prior art foams are described in greater detail in British Pat. Nos. 798,669 and 867,619.
It is known from British Pat. No. 841,825 to use a non-foaming silicone room temperature vulcanizing composition for making dental impressions.
It is known from U.S. Pat. No. 3,399,457 to use a rigid foam to form a permanently deformable bite block.